Try defining a subpattern using the "use-for=enumeration" property. This subpattern defines what a user can type to select an entry from an enumerated list or menu. The return value should be a number expressed as an integer. For example:
subpattern ChineseNumbersForMenus {use-for=enumeration}
+ (1|2|3|4|5) // your numbers in "full-width"
Hope that helps,
Carina